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1 <?xml version='1.0' encoding="UTF-8"?>
2 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.84 2011/09/04 17:53:40 swift Exp $ -->
3
4 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
5
6 <guide>
7 <title>Gentoo Linux ALSA Guide</title>
8
9 <author title="Author">
10 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
11 </author>
12 <author title="Author">
13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
14 </author>
15 <author title="Contributor">
16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
17 </author>
18
19 <abstract>
20 This document helps a user setup ALSA on Gentoo Linux.
21 </abstract>
22
23 <!-- The content of this document is licensed under the CC-BY-SA license -->
24 <!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
25 <license/>
26
27 <version>3</version>
28 <date>2012-02-13</date>
29
30 <chapter>
31 <title>Introduction</title>
32 <section>
33 <title>What is ALSA?</title>
34 <body>
35
36 <p>
37 ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides audio
38 and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to the
39 Linux operating system. ALSA is the default sound subsystem in the 3.0 and 2.6
40 kernels, thereby replacing OSS (<e>Open Sound System</e>), which was used in
41 the 2.4 kernels.
42 </p>
43
44 <p>
45 ALSA's main features include efficient support for all types of audio
46 interfaces ranging from consumer sound cards to professional sound
47 equipment, fully modularized drivers, SMP and thread safety, backward
48 compatibility with OSS and a user-space library <c>alsa-lib</c> to make
49 application development a breeze.
50 </p>
51
52 </body>
53 </section>
54 </chapter>
55
56 <chapter>
57 <title>Installing ALSA</title>
58 <section id="lspci">
59 <title>Before you proceed</title>
60 <body>
61
62 <p>
63 First, you need to know what drivers your sound card uses. In most cases, sound
64 cards (onboard and otherwise) are PCI based and <c>lspci</c> will help you in
65 digging out the required information. Please <c>emerge sys-apps/pciutils</c> to
66 get <c>lspci</c>, if you don't have it installed already. In case you have a USB
67 sound card, <c>lsusb</c> from <c>sys-apps/usbutils</c> <e>might</e> be of help.
68 For ISA cards, try using <c>sys-apps/isapnptools</c>. Also, the following pages
69 <e>may</e> help users with ISA based sound cards:
70 </p>
71
72 <ul>
73 <li>
74 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
75 Page</uri>
76 </li>
77 <li>
78 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
79 Article</uri>
80 </li>
81 <li>
82 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
83 HowTo</uri>
84 </li>
85 </ul>
86
87 <note>
88 For ease of use/explanation, we assume the user has a PCI based sound card for
89 the remainder of this guide.
90 </note>
91
92 <p>
93 We now proceed to find out details about the sound card.
94 </p>
95
96 <pre caption="Soundcard Details">
97 # <i>lspci -v | grep -i audio</i>
98 0000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
99 </pre>
100
101 <p>
102 We now know that the sound card on the machine is a Sound Blaster Live! and the
103 card manufacturer is Creative Labs. Head over to the <uri
104 link="http://bugtrack.alsa-project.org/main/index.php/Matrix:Main">ALSA
105 Soundcard Matrix</uri> page and select Creative Labs from the list. You will
106 be taken to the Creative Labs matrix page where you can see that the SB Live!
107 uses the <c>emu10k1</c> module. That is the information we need for now. If
108 you are interested in detailed information, you can click on the link next to
109 the "Details" and that will take you to the <c>emu10k1</c> specific page.
110 </p>
111
112 <p>
113 If you intend to use MIDI, then you should add <c>midi</c> to your USE flags in
114 <path>/etc/make.conf</path> before emerging any ALSA packages. Later in the
115 guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
116 </p>
117
118 </body>
119 </section>
120 <section id="kernel">
121 <title>Configuring the kernel</title>
122 <body>
123
124 <note>
125 Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Please
126 check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
127 on a 2.4 kernel.
128 </note>
129
130 <p>
131 Let us now configure the kernel to enable ALSA.
132 </p>
133
134 <impo>
135 <c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
136 then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
137 ALSA</uri>.
138 </impo>
139
140 <pre caption="Heading over to the source">
141 # <i>cd /usr/src/linux</i>
142 # <i>make menuconfig</i>
143 </pre>
144
145 <note>
146 The above example assumes that <path>/usr/src/linux</path> symlink points to
147 the kernel sources you want to use. Please ensure the same before proceeding.
148 </note>
149
150 <p>
151 Now we will look at some of the options we will have to enable in the 2.6
152 kernel to ensure proper ALSA support for our sound card.
153 </p>
154
155 <p>
156 Please note that for ease of use, all examples show ALSA built as modules. It
157 is advisable to follow the same as it then allows the use of <c>alsaconf</c>
158 which is a boon when you want to configure your card. Please do <e>not</e> skip
159 the <uri link="#alsa-config">Configuration</uri> section of this document. If
160 you still like to have options built-in, ensure that you make changes to your
161 config accordingly.
162 </p>
163
164 <pre caption="Kernel Options for ALSA">
165 Device Drivers ---&gt;
166 Sound ---&gt;
167
168 <comment>(This needs to be enabled)</comment>
169 &lt;M&gt; Sound card support
170
171 <comment>(Make sure OSS is disabled)</comment>
172 Open Sound System ---&gt;
173 &lt; &gt; Open Sound System (DEPRECATED)
174
175 <comment>(Move one step back and enter ALSA)</comment>
176 Advanced Linux Sound Architecture ---&gt;
177 &lt;M&gt; Advanced Linux Sound Architecture
178 <comment>(Select this if you want MIDI sequencing and routing)</comment>
179 &lt;M&gt; Sequencer support
180 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
181 &lt;M&gt; OSS Mixer API
182 &lt;M&gt; OSS PCM (digital audio) API
183
184 <comment>(You now have a choice of devices to enable support for. Generally,
185 you will have one type of device and not more. If you have more than one
186 sound card, please enable them all here.)</comment>
187
188 <comment>(Mostly for testing and development purposes, not needed for normal
189 users unless you know what you are doing.)</comment>
190 Generic devices ---&gt;
191
192 <comment>(For ISA Sound cards)</comment>
193 ISA devices ---&gt;
194 <comment>(IF you had the Gravis, you would select this option)</comment>
195 &lt;M&gt; Gravis UltraSound Extreme
196
197 <comment>(Move one level back and into PCI devices. Most sound cards today are
198 PCI devices)</comment>
199 PCI devices ---&gt;
200 <comment>(We now select the emu10k1 driver for our card)</comment>
201 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
202 <comment>(Or an Intel card would be)</comment>
203 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
204 <comment>(Or if you have a VIA Card)</comment>
205 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
206
207 <comment>(Move one level back and select in case you have an USB sound card)</comment>
208 USB Devices ---&gt;
209 </pre>
210
211 <p>
212 Now that your options are set, you can (re)compile the kernel and ALSA support
213 for your card should be functional once you reboot into the new kernel. Don't
214 forget to update your GRUB configuration to use the newly built kernel.
215 You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
216 see if everything is working as it should.
217 </p>
218
219 </body>
220 </section>
221 </chapter>
222
223 <chapter>
224 <title>Configuring/Testing ALSA</title>
225 <section id="alsa-utilities">
226 <title>ALSA Utilities</title>
227 <body>
228
229 <p>
230 <c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
231 programs that are highly useful, including the ALSA Initscripts. Hence we
232 strongly recommend that you install <c>alsa-utils</c>
233 </p>
234
235 <pre caption="Install alsa-utils">
236 # <i>emerge alsa-utils</i>
237 </pre>
238
239 <note>
240 If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
241 link="#initscript">ALSA Initscript</uri> section. The rest of you need to
242 configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
243 tool provided by <c>alsa-utils</c>.
244 </note>
245
246 </body>
247 </section>
248 <section id="alsa-config">
249 <title>Configuration</title>
250 <body>
251
252 <p>
253 Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
254 kernel-level autoconfiguration of your sound card. If possible, try to rely on
255 just letting your kernel automatically setup your sound card for you. Otherwise,
256 use <c>alsaconf</c> to configure your card, as shown below.
257 </p>
258
259 <note>
260 Please shut down any programs that <e>might</e> access the sound card while
261 running <c>alsaconf</c>.
262 </note>
263
264 <p>
265 To configure your sound card just type <c>alsaconf</c> in a shell as root.
266 </p>
267
268 <pre caption="Invoking alsaconf">
269 # <i>alsaconf</i>
270 </pre>
271
272 <p>
273 You will now see a neat menu guided interface that will automatically probe
274 your devices and try to find out your sound card. You will be asked to pick
275 your sound card from a list. Once that's done, it will ask you permission to
276 automatically make required changes to <path>/etc/modprobe.d/alsa.conf</path>.
277 It will then adjust your volume settings to optimum levels, run
278 <c>update-modules</c> and start the <path>/etc/init.d/alsasound</path> service.
279 Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
280 initscript.
281 </p>
282
283 </body>
284 </section>
285 <section id="initscript">
286 <title>ALSA Initscript</title>
287 <body>
288
289 <p>
290 We're now almost all setup. Whichever method you chose to install ALSA, you'll
291 need to have something load your modules or initialize ALSA and restore your
292 volume settings when your system comes up. The ALSA Initscript handles all of
293 this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
294 </p>
295
296 <pre caption="Adding ALSA to the boot runlevel">
297 # <i>rc-update add alsasound boot</i>
298 * alsasound added to runlevel boot
299 * rc-update complete.
300 </pre>
301
302 <p>
303 Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
304 SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
305 shutdown your system.
306 </p>
307
308 </body>
309 </section>
310 <section>
311 <title>Audio Group</title>
312 <body>
313
314 <p>
315 Before we move on to testing, there's one last <e>important</e> thing that needs
316 to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
317 This applies here as well ;) How? Well, most of the times you should be logged
318 in as a user and would like to listen to music or access your soundcard. For
319 that to happen, you need to be in the "audio" group. At this point, we'll add
320 users to the audio group, so that they won't have any issues when they want to
321 access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
322 as root for this to work.
323 </p>
324
325 <pre caption="Adding users to the audio group">
326 <comment>(Substitute &lt;username&gt; with your user)</comment>
327 # <i>gpasswd -a &lt;username&gt; audio </i>
328 Adding user &lt;username&gt; to group audio
329 </pre>
330
331 </body>
332 </section>
333 <section>
334 <title>Volume Check!</title>
335 <body>
336
337 <p>
338 We've completed all the setups and prerequisites, so let's fire up ALSA. If
339 you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
340 does this for you.
341 </p>
342
343 <pre caption="Start the service">
344 # <i>/etc/init.d/alsasound start</i>
345 </pre>
346
347 <p>
348 Now that the required things have been taken care of, we need to check up on
349 the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
350 purpose.
351 </p>
352
353 <pre caption="Starting alsamixer">
354 <comment>(Opens up a console program. Only required settings are shown)</comment>
355 # <i>alsamixer</i>
356 </pre>
357
358 <p>
359 This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
360 attention to the Master and PCM channels which both have an MM below them.
361 That means they are muted. If you try to play anything with <c>alsamixer</c>
362 in this state, you will not hear anything on your speakers.
363 </p>
364
365 <figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
366
367 <p>
368 Now, we shall unmute the channels, and set volume levels as needed.
369 </p>
370
371 <warn>
372 Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
373 if you want to hear some output on your speakers.
374 </warn>
375
376 <ul>
377 <li>
378 To move between channels, use your left and right arrow keys. (&lt;-
379 &amp; -&gt;)
380 </li>
381 <li>
382 To toggle mute, move to the specific channel, for example Master and press
383 the <e>m</e> key on the keyboard.
384 </li>
385 <li>
386 To increase and decrease the volume levels, use the up and down arrow keys
387 respectively.
388 </li>
389 </ul>
390
391 <note>
392 Be careful when setting your Bass and Treble values. 50 is usually a good
393 number for both. Extremely high values of Bass may cause <e>jarring</e>
394 on speakers that are not designed to handle them.
395 </note>
396
397 <p>
398 After you're all done, your ALSA Mixer should look similar to the one below.
399 Note the 00 instead of the MM and also the volume levels for some optimum
400 settings.
401 </p>
402
403 <figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
404
405 </body>
406 </section>
407 <section>
408 <title>Sound Check!</title>
409 <body>
410
411 <p>
412 Finally. Some music. If everything above is perfect, you should now be able to
413 listen to some good music. A quick way to test is to use a command line tool
414 like <c>media-sound/madplay</c>. You could also use something more well known
415 like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
416 by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
417 always, <c>emerge</c> what you need.
418 </p>
419
420 <pre caption="Getting the software">
421 <comment>(Install the applications you want)</comment>
422 # <i>emerge madplay mpg123</i>
423 <comment>(To play .ogg files)</comment>
424 # <i>emerge vorbis-tools</i>
425 </pre>
426
427 <p>
428 And then play your favorite sound track...
429 </p>
430
431 <pre caption="Playing Music">
432 # <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
433 MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
434 Title: Dread Rock
435 Artist: Paul Oakenfold
436 Album: Matrix Reloaded
437 Year: 2003
438 Genre: Soundtrack
439 Soundtrack
440 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
441
442 # <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
443 Audio Device: Advanced Linux Sound Architecture (ALSA) output
444
445 Playing: Paul Oakenfold - Dread Rock.ogg
446 Ogg Vorbis stream: 2 channel, 44100 Hz
447 Genre: Soundtrack
448 Transcoded: mp3;160
449 Title: Dread Rock
450 Artist: Paul Oakenfold
451 Date: 2003
452 Album: Matrix Reloaded
453 Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
454 </pre>
455
456 </body>
457 </section>
458 <section>
459 <title>ALSA and USE</title>
460 <body>
461
462 <p>
463 You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
464 ensure that your applications that support ALSA get built with it. Some
465 architectures like x86 and amd64 have the flag enabled by default.
466 </p>
467
468 </body>
469 </section>
470 <section>
471 <title>Issues?</title>
472 <body>
473
474 <p>
475 If for some reason you're unable to hear sound, the first thing to do would
476 be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
477 the issues lie with muted channels or low volume. Also check your Window
478 Manager's sound applet and verify that volumes are set to audible levels.
479 </p>
480
481 <p>
482 <path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
483 is your best friend. We shall just take a short look at how much info is made
484 available to us there.
485 </p>
486
487 <pre caption="Fun with /proc/asound">
488 <comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
489 picked up your sound card fine.)</comment>
490 # <i>cat /proc/asound/cards</i>
491 0 [Live ]: EMU10K1 - Sound Blaster Live!
492 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
493
494 <comment>(This displays the current running ALSA version)</comment>
495 # <i>cat /proc/asound/version</i>
496 Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
497
498 <comment>(ALSA OSS emulation details)</comment>
499 # <i>cat /proc/asound/oss/sndstat</i>
500 Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
501 Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
502 Config options: 0
503
504 Installed drivers:
505 Type 10: ALSA emulation
506
507 Card config:
508 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
509
510 Audio devices:
511 0: EMU10K1 (DUPLEX)
512
513 Synth devices: NOT ENABLED IN CONFIG
514
515 Midi devices:
516 0: EMU10K1 MPU-401 (UART)
517
518 Timers:
519 7: system timer
520
521 Mixers:
522 0: SigmaTel STAC9721/23
523 </pre>
524
525 <!-- TODO: remove this a few months after alsa-driver leaves the tree -->
526
527 <p>
528 The other most common issue users face is the dreaded "Unknown symbol in module"
529 error. An example of the same is shown below.
530 </p>
531
532 <pre caption="Unknown Symbol in module error">
533 # <i>/etc/init.d/alsasound start</i>
534 * Loading ALSA modules ...
535 * Loading: snd-card-0 ... [ ok ]
536 * Loading: snd-pcm-oss ...
537 WARNING: Error inserting snd_mixer_oss
538 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
539 symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
540 snd_pcm_oss
541 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
542 symbol in module, or unknown parameter (see dmesg)
543 [ !! ]
544 * Loading: snd-mixer-oss ...
545 FATAL: Error inserting snd_mixer_oss
546 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
547 symbol in module, or unknown parameter (see dmesg)
548 [ !! ]
549 * Loading: snd-seq ... [ ok ]
550 * Loading: snd-emu10k1-synth ... [ ok ]
551 * Loading: snd-seq-midi ... [ ok ]
552 * Restoring Mixer Levels ... [ ok ]
553 </pre>
554
555 <p>
556 And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
557 see:
558 </p>
559
560 <pre caption="dmesg output">
561 <comment>(Only relevant portions are shown below)</comment>
562 # <i>dmesg | less</i>
563 ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
564 snd_mixer_oss: Unknown symbol snd_unregister_oss_device
565 snd_mixer_oss: Unknown symbol snd_register_oss_device
566 snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
567 snd_mixer_oss: Unknown symbol snd_oss_info_register
568 snd_pcm_oss: Unknown symbol snd_unregister_oss_device
569 snd_pcm_oss: Unknown symbol snd_register_oss_device
570 snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
571 snd_pcm_oss: Unknown symbol snd_oss_info_register
572 snd_mixer_oss: Unknown symbol snd_unregister_oss_device
573 snd_mixer_oss: Unknown symbol snd_register_oss_device
574 snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
575 snd_mixer_oss: Unknown symbol snd_oss_info_register
576 </pre>
577
578 <p>
579 The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
580 ALSA because when you unmerge <c>alsa-driver</c> the module files are config
581 protected and hence get left behind. So, when you switch to in-kernel
582 drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
583 in-kernel modules thus causing the above errors.
584 </p>
585
586 <p>
587 The solution is quite easy. We just need to manually remove the problem causing
588 directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
589 kernel version and not the current one!
590 </p>
591
592 <pre caption="Removing the alsa-driver modules">
593 # <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
594 </pre>
595
596 <p>
597 Another reason for error messages similar to the ones above could be a file in
598 <path>/etc/modprobe.d</path> supplying a <c>device_mode</c> parameter when it
599 isn't required. Confirm that this is indeed the issue and find out which file
600 is the culprit.
601 </p>
602
603 <pre caption="Confirming and searching for device_mode">
604 <comment>(Check dmesg to confirm)</comment>
605 # <i>dmesg | grep device_mode</i>
606 snd: Unknown parameter `device_mode'
607 <comment>(Now, to get to the source of the issue)</comment>
608 # <i>grep device_mode /etc/modprobe.d/*</i>
609 </pre>
610
611 <p>
612 Usually it is a file called <path>alsa</path> with the line <c>options snd
613 device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
614 and that should take care of this issue.
615 </p>
616
617 <!-- End of removal notice -->
618
619 </body>
620 </section>
621 </chapter>
622
623 <chapter>
624 <title>Other things ALSA</title>
625 <section id="midi">
626 <title>Setting up MIDI support</title>
627 <body>
628
629 <p>
630 First, check to make sure that you enabled the <c>midi</c> USE flag in
631 <path>/etc/make.conf</path>. If you didn't, go ahead and add it now. You will
632 also need to re-emerge any ALSA packages that use the <c>midi</c> flag, such as
633 <c>alsa-lib</c> and <c>alsa-utils</c>.
634 </p>
635
636 <p>
637 If your sound card is one of those that come with on-board MIDI synthesizers
638 and you would like to listen to some .mid files, you have to install
639 <c>awesfx</c> which is basically a set of utilities for controlling the AWE32
640 driver. We need to install it first. If you don't have a hardware synthesizer,
641 you can use a virtual one. Please see the section on
642 <uri link="#vsynth">Virtual Synthesizers</uri> for more information.
643 </p>
644
645 <pre caption="Installing awesfx">
646 # <i>emerge awesfx</i>
647 </pre>
648
649 <note>
650 You will need to copy over SoundFont (SF2) files from your sound card's driver
651 CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
652 example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
653 </note>
654
655 <p>
656 After copying over the Soundfont files, we can then play a midi file as shown.
657 You can also add the <c>asfxload</c> command to
658 <path>/etc/conf.d/local.start</path>, so that the sound font is loaded
659 every time the system starts up.
660 </p>
661
662 <note>
663 <path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
664 be the same in your machine. They are just an example. Please be careful to
665 change the path to suit your machine.
666 </note>
667
668 <pre caption="Loading Soundfonts">
669 <comment>(First, copy the Soundfont)</comment>
670 # <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
671 <comment>(Or get it from your SoundBlaster CD)</comment>
672 # <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
673 <comment>(We load the specific Soundfont)</comment>
674 # <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
675 </pre>
676
677 <p>
678 You can now play midi files using a program like <c>aplaymidi</c>. Run
679 <c>aplaymidi -l</c> to get a list of available ports and then pick one
680 to play the file on.
681 </p>
682
683 <pre caption="Playing MIDI">
684 <comment>(Check open ports)</comment>
685 # <i>aplaymidi -l</i>
686 Port Client name Port name
687 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
688 65:0 Emu10k1 WaveTable Emu10k1 Port 0
689 65:1 Emu10k1 WaveTable Emu10k1 Port 1
690 65:2 Emu10k1 WaveTable Emu10k1 Port 2
691 65:3 Emu10k1 WaveTable Emu10k1 Port 3
692 <comment>(Pick a port, and play a mid file)</comment>
693 # <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
694 </pre>
695
696 </body>
697 </section>
698 <section id="vsynth">
699 <title>Virtual Synthesizers</title>
700 <body>
701
702 <p>
703 If your sound card lacks a hardware synthesizer, you could use a virtual one
704 like <c>timidity++</c>. Installation is a breeze.
705 </p>
706
707 <pre caption="Installing timidity++">
708 # <i>emerge timidity++</i>
709 </pre>
710
711 <p>
712 For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
713 install some sound font packages for you. There are a few other font packages
714 available in Portage, such as <c>timidity-freepats</c> and
715 <c>timidity-eawpatches</c>. You can have multiple sound font configurations
716 installed, and you can place your own in <path>/usr/share/timidity/</path>. To
717 switch between different timidity configurations, you should use
718 <c>eselect</c>.
719 </p>
720
721 <pre caption="Changing configurations">
722 # <i>eselect timidity list</i>
723 # <i>eselect timidity set eawpatches</i>
724 </pre>
725
726 <p>
727 Don't forget to add <c>timidity</c> to the default runlevel.
728 </p>
729
730 <pre caption="Adding timidity to the default runlevel">
731 # <i>rc-update add timidity default</i>
732 # <i>/etc/init.d/timidity start</i>
733 </pre>
734
735 <p>
736 You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
737 </p>
738
739 </body>
740 </section>
741 <section>
742 <title>Tools and Firmware</title>
743 <body>
744
745 <p>
746 Some specific sound cards can benefit from certain tools provided by the
747 <c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
748 a simple <c>emerge</c>.
749 </p>
750
751 <pre caption="Installing ALSA Tools">
752 # <i>emerge alsa-tools</i>
753 </pre>
754
755 </body>
756 </section>
757 <section>
758 <title>Multiple sound cards</title>
759 <body>
760
761 <p>
762 You can have more than one sound card in your system simultaneously, provided
763 that you have built ALSA as modules in your kernel. You just need to specify
764 which should be started first in <path>/etc/modprobe.d/alsa.conf</path>. Your cards
765 are identified by their driver names inside this file. 0 is the first card, 1 is
766 the second, and so on. Here's an example for a system with two sound cards.
767 </p>
768
769 <pre caption="Two sound cards in /etc/modprobe.d/alsa.conf">
770 options snd-emu10k1 index=0
771 options snd-via82xx index=1
772 </pre>
773
774 <p>
775 Or, if you have two cards that use the same driver, you specify them on the same
776 line, using comma-separated numbers. Here's an example for a system with three
777 sound cards, two of which are the same Intel High Definition Audio card.
778 </p>
779
780 <pre caption="Multiple sound cards in /etc/modprobe.d/alsa.conf">
781 options snd-ymfpci index=0
782 options snd-hda-intel index=1,2
783 </pre>
784
785 </body>
786 </section>
787 <section>
788 <title>Plugins</title>
789 <body>
790
791 <p>
792 You may want to install some plugins for extra functionality.
793 <c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
794 output, a sample rate converter, jack (a low-latency audio server), and an
795 encoder that lets you output 6-channel audio through digital S/PDIF connections
796 (both optical and coaxial). You can choose which of its plugins you want
797 installed by adding their USE flags to <path>/etc/portage/package.use</path>.
798 </p>
799
800 <pre caption="Installing alsa-plugins">
801 # <i>emerge -avt alsa-plugins</i>
802 </pre>
803
804 </body>
805 </section>
806 <section>
807 <title>A big thank you to...</title>
808 <body>
809
810 <p>
811 Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
812 Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
813 John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
814 </p>
815
816 </body>
817 </section>
818 <section>
819 <title>References</title>
820 <body>
821
822 <ul>
823 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
824 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
825 </ul>
826
827 </body>
828 </section>
829 </chapter>
830 </guide>

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